maple_tree: add test for mtree_dup()

Add test for mtree_dup().

Test by duplicating different maple trees and then comparing the two
trees.  Includes tests for duplicating full trees and memory allocation
failures on different nodes.

Link: https://lkml.kernel.org/r/20231027033845.90608-6-zhangpeng.00@bytedance.comSigned-off-by: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/radix-tree/maple.c

@@ -35857,6 +35857,363 @@ static noinline void __init check_locky(struct maple_tree *mt)
 	mt_clear_in_rcu(mt);
 }
 
+/*
+ * Compares two nodes except for the addresses stored in the nodes.
+ * Returns zero if they are the same, otherwise returns non-zero.
+ */
+static int __init compare_node(struct maple_enode *enode_a,
+			       struct maple_enode *enode_b)
+{
+	struct maple_node *node_a, *node_b;
+	struct maple_node a, b;
+	void **slots_a, **slots_b; /* Do not use the rcu tag. */
+	enum maple_type type;
+	int i;
+
+	if (((unsigned long)enode_a & MAPLE_NODE_MASK) !=
+	    ((unsigned long)enode_b & MAPLE_NODE_MASK)) {
+		pr_err("The lower 8 bits of enode are different.\n");
+		return -1;
+	}
+
+	type = mte_node_type(enode_a);
+	node_a = mte_to_node(enode_a);
+	node_b = mte_to_node(enode_b);
+	a = *node_a;
+	b = *node_b;
+
+	/* Do not compare addresses. */
+	if (ma_is_root(node_a) || ma_is_root(node_b)) {
+		a.parent = (struct maple_pnode *)((unsigned long)a.parent &
+						  MA_ROOT_PARENT);
+		b.parent = (struct maple_pnode *)((unsigned long)b.parent &
+						  MA_ROOT_PARENT);
+	} else {
+		a.parent = (struct maple_pnode *)((unsigned long)a.parent &
+						  MAPLE_NODE_MASK);
+		b.parent = (struct maple_pnode *)((unsigned long)b.parent &
+						  MAPLE_NODE_MASK);
+	}
+
+	if (a.parent != b.parent) {
+		pr_err("The lower 8 bits of parents are different. %p %p\n",
+			a.parent, b.parent);
+		return -1;
+	}
+
+	/*
+	 * If it is a leaf node, the slots do not contain the node address, and
+	 * no special processing of slots is required.
+	 */
+	if (ma_is_leaf(type))
+		goto cmp;
+
+	slots_a = ma_slots(&a, type);
+	slots_b = ma_slots(&b, type);
+
+	for (i = 0; i < mt_slots[type]; i++) {
+		if (!slots_a[i] && !slots_b[i])
+			break;
+
+		if (!slots_a[i] || !slots_b[i]) {
+			pr_err("The number of slots is different.\n");
+			return -1;
+		}
+
+		/* Do not compare addresses in slots. */
+		((unsigned long *)slots_a)[i] &= MAPLE_NODE_MASK;
+		((unsigned long *)slots_b)[i] &= MAPLE_NODE_MASK;
+	}
+
+cmp:
+	/*
+	 * Compare all contents of two nodes, including parent (except address),
+	 * slots (except address), pivots, gaps and metadata.
+	 */
+	return memcmp(&a, &b, sizeof(struct maple_node));
+}
+
+/*
+ * Compare two trees and return 0 if they are the same, non-zero otherwise.
+ */
+static int __init compare_tree(struct maple_tree *mt_a, struct maple_tree *mt_b)
+{
+	MA_STATE(mas_a, mt_a, 0, 0);
+	MA_STATE(mas_b, mt_b, 0, 0);
+
+	if (mt_a->ma_flags != mt_b->ma_flags) {
+		pr_err("The flags of the two trees are different.\n");
+		return -1;
+	}
+
+	mas_dfs_preorder(&mas_a);
+	mas_dfs_preorder(&mas_b);
+
+	if (mas_is_ptr(&mas_a) || mas_is_ptr(&mas_b)) {
+		if (!(mas_is_ptr(&mas_a) && mas_is_ptr(&mas_b))) {
+			pr_err("One is MAS_ROOT and the other is not.\n");
+			return -1;
+		}
+		return 0;
+	}
+
+	while (!mas_is_none(&mas_a) || !mas_is_none(&mas_b)) {
+
+		if (mas_is_none(&mas_a) || mas_is_none(&mas_b)) {
+			pr_err("One is MAS_NONE and the other is not.\n");
+			return -1;
+		}
+
+		if (mas_a.min != mas_b.min ||
+		    mas_a.max != mas_b.max) {
+			pr_err("mas->min, mas->max do not match.\n");
+			return -1;
+		}
+
+		if (compare_node(mas_a.node, mas_b.node)) {
+			pr_err("The contents of nodes %p and %p are different.\n",
+			       mas_a.node, mas_b.node);
+			mt_dump(mt_a, mt_dump_dec);
+			mt_dump(mt_b, mt_dump_dec);
+			return -1;
+		}
+
+		mas_dfs_preorder(&mas_a);
+		mas_dfs_preorder(&mas_b);
+	}
+
+	return 0;
+}
+
+static __init void mas_subtree_max_range(struct ma_state *mas)
+{
+	unsigned long limit = mas->max;
+	MA_STATE(newmas, mas->tree, 0, 0);
+	void *entry;
+
+	mas_for_each(mas, entry, limit) {
+		if (mas->last - mas->index >=
+		    newmas.last - newmas.index) {
+			newmas = *mas;
+		}
+	}
+
+	*mas = newmas;
+}
+
+/*
+ * build_full_tree() - Build a full tree.
+ * @mt: The tree to build.
+ * @flags: Use @flags to build the tree.
+ * @height: The height of the tree to build.
+ *
+ * Build a tree with full leaf nodes and internal nodes. Note that the height
+ * should not exceed 3, otherwise it will take a long time to build.
+ * Return: zero if the build is successful, non-zero if it fails.
+ */
+static __init int build_full_tree(struct maple_tree *mt, unsigned int flags,
+		int height)
+{
+	MA_STATE(mas, mt, 0, 0);
+	unsigned long step;
+	int ret = 0, cnt = 1;
+	enum maple_type type;
+
+	mt_init_flags(mt, flags);
+	mtree_insert_range(mt, 0, ULONG_MAX, xa_mk_value(5), GFP_KERNEL);
+
+	mtree_lock(mt);
+
+	while (1) {
+		mas_set(&mas, 0);
+		if (mt_height(mt) < height) {
+			mas.max = ULONG_MAX;
+			goto store;
+		}
+
+		while (1) {
+			mas_dfs_preorder(&mas);
+			if (mas_is_none(&mas))
+				goto unlock;
+
+			type = mte_node_type(mas.node);
+			if (mas_data_end(&mas) + 1 < mt_slots[type]) {
+				mas_set(&mas, mas.min);
+				goto store;
+			}
+		}
+store:
+		mas_subtree_max_range(&mas);
+		step = mas.last - mas.index;
+		if (step < 1) {
+			ret = -1;
+			goto unlock;
+		}
+
+		step /= 2;
+		mas.last = mas.index + step;
+		mas_store_gfp(&mas, xa_mk_value(5),
+				GFP_KERNEL);
+		++cnt;
+	}
+unlock:
+	mtree_unlock(mt);
+
+	MT_BUG_ON(mt, mt_height(mt) != height);
+	/* pr_info("height:%u number of elements:%d\n", mt_height(mt), cnt); */
+	return ret;
+}
+
+static noinline void __init check_mtree_dup(struct maple_tree *mt)
+{
+	DEFINE_MTREE(new);
+	int i, j, ret, count = 0;
+	unsigned int rand_seed = 17, rand;
+
+	/* store a value at [0, 0] */
+	mt_init_flags(mt, 0);
+	mtree_store_range(mt, 0, 0, xa_mk_value(0), GFP_KERNEL);
+	ret = mtree_dup(mt, &new, GFP_KERNEL);
+	MT_BUG_ON(&new, ret);
+	mt_validate(&new);
+	if (compare_tree(mt, &new))
+		MT_BUG_ON(&new, 1);
+
+	mtree_destroy(mt);
+	mtree_destroy(&new);
+
+	/* The two trees have different attributes. */
+	mt_init_flags(mt, 0);
+	mt_init_flags(&new, MT_FLAGS_ALLOC_RANGE);
+	ret = mtree_dup(mt, &new, GFP_KERNEL);
+	MT_BUG_ON(&new, ret != -EINVAL);
+	mtree_destroy(mt);
+	mtree_destroy(&new);
+
+	/* The new tree is not empty */
+	mt_init_flags(mt, 0);
+	mt_init_flags(&new, 0);
+	mtree_store(&new, 5, xa_mk_value(5), GFP_KERNEL);
+	ret = mtree_dup(mt, &new, GFP_KERNEL);
+	MT_BUG_ON(&new, ret != -EINVAL);
+	mtree_destroy(mt);
+	mtree_destroy(&new);
+
+	/* Test for duplicating full trees. */
+	for (i = 1; i <= 3; i++) {
+		ret = build_full_tree(mt, 0, i);
+		MT_BUG_ON(mt, ret);
+		mt_init_flags(&new, 0);
+
+		ret = mtree_dup(mt, &new, GFP_KERNEL);
+		MT_BUG_ON(&new, ret);
+		mt_validate(&new);
+		if (compare_tree(mt, &new))
+			MT_BUG_ON(&new, 1);
+
+		mtree_destroy(mt);
+		mtree_destroy(&new);
+	}
+
+	for (i = 1; i <= 3; i++) {
+		ret = build_full_tree(mt, MT_FLAGS_ALLOC_RANGE, i);
+		MT_BUG_ON(mt, ret);
+		mt_init_flags(&new, MT_FLAGS_ALLOC_RANGE);
+
+		ret = mtree_dup(mt, &new, GFP_KERNEL);
+		MT_BUG_ON(&new, ret);
+		mt_validate(&new);
+		if (compare_tree(mt, &new))
+			MT_BUG_ON(&new, 1);
+
+		mtree_destroy(mt);
+		mtree_destroy(&new);
+	}
+
+	/* Test for normal duplicating. */
+	for (i = 0; i < 1000; i += 3) {
+		if (i & 1) {
+			mt_init_flags(mt, 0);
+			mt_init_flags(&new, 0);
+		} else {
+			mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE);
+			mt_init_flags(&new, MT_FLAGS_ALLOC_RANGE);
+		}
+
+		for (j = 0; j < i; j++) {
+			mtree_store_range(mt, j * 10, j * 10 + 5,
+					  xa_mk_value(j), GFP_KERNEL);
+		}
+
+		ret = mtree_dup(mt, &new, GFP_KERNEL);
+		MT_BUG_ON(&new, ret);
+		mt_validate(&new);
+		if (compare_tree(mt, &new))
+			MT_BUG_ON(&new, 1);
+
+		mtree_destroy(mt);
+		mtree_destroy(&new);
+	}
+
+	/* Test memory allocation failed. */
+	mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE);
+	for (i = 0; i < 30; i += 3) {
+		mtree_store_range(mt, j * 10, j * 10 + 5,
+					  xa_mk_value(j), GFP_KERNEL);
+	}
+
+	/* Failed at the first node. */
+	mt_init_flags(&new, MT_FLAGS_ALLOC_RANGE);
+	mt_set_non_kernel(0);
+	ret = mtree_dup(mt, &new, GFP_NOWAIT);
+	mt_set_non_kernel(0);
+	MT_BUG_ON(&new, ret != -ENOMEM);
+	mtree_destroy(mt);
+	mtree_destroy(&new);
+
+	/* Random maple tree fails at a random node. */
+	for (i = 0; i < 1000; i += 3) {
+		if (i & 1) {
+			mt_init_flags(mt, 0);
+			mt_init_flags(&new, 0);
+		} else {
+			mt_init_flags(mt, MT_FLAGS_ALLOC_RANGE);
+			mt_init_flags(&new, MT_FLAGS_ALLOC_RANGE);
+		}
+
+		for (j = 0; j < i; j++) {
+			mtree_store_range(mt, j * 10, j * 10 + 5,
+					  xa_mk_value(j), GFP_KERNEL);
+		}
+		/*
+		 * The rand() library function is not used, so we can generate
+		 * the same random numbers on any platform.
+		 */
+		rand_seed = rand_seed * 1103515245 + 12345;
+		rand = rand_seed / 65536 % 128;
+		mt_set_non_kernel(rand);
+
+		ret = mtree_dup(mt, &new, GFP_NOWAIT);
+		mt_set_non_kernel(0);
+		if (ret != 0) {
+			MT_BUG_ON(&new, ret != -ENOMEM);
+			count++;
+			mtree_destroy(mt);
+			continue;
+		}
+
+		mt_validate(&new);
+		if (compare_tree(mt, &new))
+			MT_BUG_ON(&new, 1);
+
+		mtree_destroy(mt);
+		mtree_destroy(&new);
+	}
+
+	/* pr_info("mtree_dup() fail %d times\n", count); */
+	BUG_ON(!count);
+}
+
 extern void test_kmem_cache_bulk(void);
 
 void farmer_tests(void)
@@ -35904,6 +36261,10 @@ void farmer_tests(void)
 	check_null_expand(&tree);
 	mtree_destroy(&tree);
 
+	mt_init_flags(&tree, 0);
+	check_mtree_dup(&tree);
+	mtree_destroy(&tree);
+
 	/* RCU testing */
 	mt_init_flags(&tree, 0);
 	check_erase_testset(&tree);